Noob with a new-to-me LX470

[patmeclark]

Hello all! New(ish) to the forums and just nabbed myself a new rig. 2005 LX470 w/188k miles. I'd been scouring for one for about 6 months and finally found one...1,000 miles away in NM. So, I jumped on a flight, did the deal and took a 16 hour road trip back to San Jose, CA. The drive was excellent, smooth and steady, all gauges holding super steady the whole drive. I think I scored a pretty good deal, $13,500 when everything in CA was at least 3k more expensive.

The rig is stock, save a radar detector and slightly larger tires then stock (275/65/R18), though still road tires. It's also in great condition, a few minor dings on the paint, some scratches on the front bumper corners, and a couple tears in the driver door leather. All other leather, seats, plastic, etc. is almost new, about as good as one could expect from a 12 YO rig. First owner had it for 180k miles and serviced it every 5k on the dot, every dealership recommended item done, including timing belt at 90 and 178k. Second owner only had it for 8k miles and did a single oil change on his own.

However, there is a single (fingers crossed) issue that I hope some of you can chime in on. Apparently the second owner did the DVD bypass hack and, perhaps, didn't do it right. Some lights on the dash were on (more details in a minute) and the AHC did not go to high or low. The guy reassured me that this happened after he did the hack and that it was all working when he bought it. Given the overall condition of the car and the service history, and the fact the guy seemed a straight shooter, I took his word.

So, here's what I have:

When purchased
- e brake light on all the time
- VSC TRAC on solid
- VSC OFF on solid
- AHC OFF flashing

I opened up the head unit and found:
- red wire with white stripe severed with one end grounded (end coming from the car and not the head unit. I spliced this back together.
- violet/brown wires (2) (hard to tell what color they actually are) severed but put back together. I believe they were put back correctly, but I swapped them to see if any of the lights changed, didn't seem to do anything, but I also didn't have a code reader yet.
- traced the violet/brown wires and found one of them close to a blue wire with white stripe, so I traced one of the violet/brown wires close to that on both car and head unit side, spliced that one, then spliced the other one.

After this work, the VSC lights were still on, but brake light turned off when e brake disengaged, but the VGRS light came on, sometimes solid and sometimes flashing. It did go off after driving for 10 minutes or so, but then comes back on upon starting the car.

Then I got my hands on a scanner and pulled 2 codes:
C1340 - CDL open circuit (I drove and engaged the CDL fine, so not sure why this was on)
C1291 - as best I can tell, something to do with the transmission (C1291 Lexus Auto Trouble Code With All Car Models | Auto Trouble Codes - AutoTroubleCode.com)

I tried to clear both, and c1340 went away, but 1291 did not clear. I also checked all the fuses in the box by the battery, even swapped AHC and ABS to see if that was the problem, but did not change anything. I did a forum search for C1291 and only one thread came up, and it was along with a bunch of other codes and not helpful for my situation.

To reiterate, current situation is:
-VSC TRAC on solid
-VSC OFF on solid
-VGRS flashing on startup, but goes away after 10 mins of driving
-AHC OFF flashing. If you press up or down, green dash light flashes twice then stops, no height change
-Code C1291 still present and will not clear

So, I'm hoping that maybe someone has encountered this, or at the least can give some pointers on where to start. I'd like to avoid the $170 diagnostic fee if possible, especially if it's something simple to fix. The above site lists checking the PCM for 5v, but I don't even know where that is. Don't have a repair manual yet, but should be getting soon hopefully.

Anyway, thanks in advance for the help. I've already gleaned a ton of great info from the site before purchasing the rig.

Patrick

 

[patmeclark]

Here's a few photos
First, of the rig on the drive back to CA

Here is the wiring repair:

 

[FranceJohnson]

I would start by bleeding the AHC fluid. There is a thread which popped up in that last few days updating the part number to this, and how many you will need. This job is pretty easy, definitely helps if you have someone else up at the engine keeping the fluid topped off.

When you turn on the CDL, the VSC TRAC lights will normally come on, and stay on until the CDL is turned off and the vehicle is restarted. Given that you had a code associated with the CDL, it could be that the truck isn't seeing the CLD is disengaged. If I remember correctly, there is some type of relay or sensor on the transfer case which can be faulty, this might be your issue.

VGRS could be a bad clock spring, I don't know I would necessarily sweat that until it starts acting up and re-clocking your steering in weird positions.

FWIW, We had a bunch of weird gremlins when we bought our truck, mostly stuff with the power mirrors. The guy we bought it from never got the tires dirty or put the truck through the paces in nearly 16 years. After about a month of blasting through the desert, things started being shaken back to life. Could very well be that a lot of this stuff hasn't been used in some time and need to be exercised a little more.

 

[patmeclark]

I would start by bleeding the AHC fluid. There is a thread which popped up in that last few days updating the part number to this, and how many you will need. This job is pretty easy, definitely helps if you have someone else up at the engine keeping the fluid topped off.

When you turn on the CDL, the VSC TRAC lights will normally come on, and stay on until the CDL is turned off and the vehicle is restarted. Given that you had a code associated with the CDL, it could be that the truck isn't seeing the CLD is disengaged. If I remember correctly, there is some type of relay or sensor on the transfer case which can be faulty, this might be your issue.

VGRS could be a bad clock spring, I don't know I would necessarily sweat that until it starts acting up and re-clocking your steering in weird positions.

FWIW, We had a bunch of weird gremlins when we bought our truck, mostly stuff with the power mirrors. The guy we bought it from never got the tires dirty or put the truck through the paces in nearly 16 years. After about a month of blasting through the desert, things started being shaken back to life. Could very well be that a lot of this stuff hasn't been used in some time and need to be exercised a little more.

Thanks for the input. I'll plan to do an AHC fluid flush and see if that helps.

Any way to test the CDL relay, or is it a replace and cross fingers situation?

Also, do you think that the VSC lights and the AHC not working are related or independent?

Lastly, I have a cheapo Innova 3030 scanner, I just read on another forum that cheapos may not pickup all the codes, is that correct?

 

[FranceJohnson]

There is always ways to test relays with a multimeter and +12v power source (I use a 14.4V power drill battery). Google should give you the basics, but you will need to know the input/outputs of the specific relay; which I couldn't tell you.

I would have to assume the AHC and the VSC lights are unrelated; they are two separate systems. Typically an old pump, or old fluid will have trouble building pressure going into high mode. It is a little strange that it doesn't want to go into Low mode either. I think this is probably more of a case of it being unused/unexercised. Pushing new fluid through the system might help kick out some junk.

I would suggest snagging a USB to OBD-II dongle, I think the common one used on Amazon is like $13. If you do some snooping around, you can find the TECHSTREAM download. This is really what you need, if you want to see what heck is going on with your truck. This might even allow you to test and fire relays. It will also show you your AHC pressures, and just about everything going on inside you engine. Caveat, it seems to require a Windows XP system to operate, which isn't really common any more. You can find info on that in separate threads.

I hate any dash lights, so I understand the desire to figure them out; but it doesn't seem like anyone one of them are a big deal and aren't going to keep you from running around.

 

[patmeclark]

Thanks again! I have it on my list to check out techstream, I've seen it mentioned a bunch and kinda figured that was the right tool for deeper diagnostics.

Yeah, I'm not terribly concerned about the lights themselves, mostly want my AHC working I'll update as things change, hopefully for the better.

 

[fooldall1]

Nice, great looking truck!

 

[patmeclark]

Nice, great looking truck!

Thanks! I'm looking forward to getting it out in the dirt and seeing what she's made of.

 

[patmeclark]

Update:
Bit the bullet and took the truck into the dealer for diagnostics. Turns out I have a bad left front height sensor. They also did a zero point calibration that seemed to turn off the VGRS and VSC lights. The AHC "off" light flashes here or there, but the funny thing is it actually works now...kinda. I can coax it into high in 4HI and extra high in 4LO, but it doesn't work every time. I kinda have to juggle between N and D and R when not moving, but it seems to go relatively easy when driving at slow speeds. It won't go into low though. I did check the graduations from N to HI and i have 6 (sounds like a minimum of 7 between LO and HI, so i hope i'm ok - once it goes into LO i'll check it again, of course).

I'm planning to switch just the sensor for the Dorman 924755 since it seems people are having good experiences with it thus far, anything i'm missing?

PADDO wrote something about having to dial in the new sensor with Techstream, is that required or just for geeking out? I don't have Techstream yet and i don't really have a laptop to run it on (have an old one but i kinda doubt its up to the challenge).